Validation for edit comment length

[Oaphi]

Closes #1258

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• [x] character count for edit comment fields;
• [x] site setting for configuring max edit comment length;
• [x] direct edit comment length validation for single post updates;
• [x] suggested edit comment length validation;
• [x] internationalization for the error message;
• [x] direct edit comment length validation for push-to-network updates;
• [x] fix updates to Help Center with network push option turned on;

• [x] add ability to resolve edit validation issues when approving pending edits;

Validation error display with > 1 max characters limit:

Site setting for updating the new limit (255 by default):

Validation error display with = 1 max character limit:

Validation error display when approving a suggested edit fails due to validation:

Additional changes include:

• formatting settings for VSCode users;
• fix for incorrect char count value on initial render when editing post titles;
• fix for min_title_length view helper for Help Center posts (min length for them is always 1);